Controlled electrochemical deposition of magnetostrictive Fe1 − xGax alloys
By Reddy, K. Sai Madhukar; Estrine, Eliot C.; Lim, Dong-Ha; Smyrl, William H. & Stadler, Bethanie J.H.
Published in Electrochemistry Communications
2012
Abstract
In this study, using steady-state electrochemistry at a rotating disk electrode, a deposition mechanism for giant magnetostrictive Fe1 - xGax alloys is proposed in which the formation of an adsorbed monovalent [Fe(I)]ads intermediate is determined to be the rate-determining step. In subsequent steps, this intermediate either gets reduced to iron or catalyzes the reduction of gallium by forming an adsorbed [Ga(III)–Fe(I)]ads intermediate. In line with the proposed mechanism, it was experimentally shown that the differences in the mass-transport rates of Fe(II) species determined the thin film composition. Therefore, this study has made possible a controllable and reproducible deposition of Fe1 - xGax thin films with compositions in the entire range of interest (15%–30% Ga). As-grown Fe80Ga20 thin films were found to have magnetostriction constants of ~ 112 ppm.